An example of this application is the electrical testing of insulating gloves of the type used by electricians and utility linemen for performing live line maintenance has been carried out for many years in an effort to detect holes or flaws in the glove to ensure that the same are safe to prevent electrical shock injury to the workmen. One of the usual procedures for testing such gloves is to partially immerse the glove in a tank of conductive liquid, usually water. An electrode is inserted into the glove which is filled with a conductive liquid to the same level as in the tank. During the test the tank containing the conductive liquid is at another electrical potential with respect to the glove electrode. The potential difference (an electrical stress) will cause a breakdown in the glove at the damaged area. This breakdown will actuate a signal or will be visible or audible to the workman performing the glove testing procedure.
Although such test procedures usually are satisfactory for many glove tests, it has the disadvantage of placing electrical stresses at the junction of the water surface and cuff of the glove. These stresses at the water surface will reach a level whereby the surrounding air is ionized resulting in the production of ozone and corona. Ozone is very destructive to insulating gloves made of natural rubber. This high stress placed at the cuff area results in excessive glove failure during tests. These existing tests also require the use of gloves having excessively long cuff areas to enable the glove to be tested. This excessive length cuff on the glove, in addition to increasing the cost of the glove, makes the gloves more burdensome and awkward for the workmen wearing the gloves.
Another problem with prior glove testing devices is that the electrode which is inserted into the interior of an immersed glove is exposed together with other metal parts on the test equipment. This exposure provides a relatively short discharge path across which an electric arc can travel shorting out the equipment and in some circumstances may cause possible injury to a workman performing the glove test.
Another disadvantage of the prior glove test equipment is the difficulty in testing gloves at different potential where cuff length would have to be adjusted.